Add support for virtual displays

ui/display/chromeos/update_display_configuration_task.h

Index: ui/display/chromeos/update_display_configuration_task.h
diff --git a/ui/display/chromeos/update_display_configuration_task.h b/ui/display/chromeos/update_display_configuration_task.h
index 7b8272e750411b2f65531bba52998a4f635c5778..cd7075253021116c752792d9a63653b81367f77e 100644
--- a/ui/display/chromeos/update_display_configuration_task.h
+++ b/ui/display/chromeos/update_display_configuration_task.h
@@ -35,6 +35,10 @@ class DISPLAY_EXPORT UpdateDisplayConfigurationTask {
                                  const ResponseCallback& callback);
   ~UpdateDisplayConfigurationTask();
 
+  void set_virtual_display_snapshots(std::vector<DisplaySnapshot*> snapshots) {
+    virtual_display_snapshots_ = snapshots;
+  }
+
   void Run();
 
  private:
@@ -92,6 +96,9 @@ class DISPLAY_EXPORT UpdateDisplayConfigurationTask {
   // List of updated displays.
   std::vector<DisplaySnapshot*> cached_displays_;
 
+  // Unowned vector of virtual displays to be added when doing the task.
+  std::vector<DisplaySnapshot*> virtual_display_snapshots_;
+
   gfx::Size framebuffer_size_;
 
   scoped_ptr<ConfigureDisplaysTask> configure_task_;